Direct detection of closely spaced optical FM-FDM Gb/s microwave PSK signals

A modulation scheme combining microwave phase-shift-keyed (PSK) and optical frequency modulation (FM) techniques is used in a two-channel optical frequency-division-multiplexed (FDM) system. Optical filtering and FM demodulation are carried out by a tunable fiber Fabry-Perot etalon. A transmission rate of 2 Gb/s and a channel spacing of less than 30 GHz are achieved with a crosstalk level of about -25 dB. This work shows that the modulation technique of combining optical FM/FDM and RF/microwave subcarrier multiplexing is transparent to either digital or analog signals. The modulation technique not only avoids the low-frequency nonuniform FM response problem, but also facilitates close optical channel spacing.<<ETX>>

[1]  K. Runge,et al.  4 Gb/s Subcarrier Multiplexed Transmission over 30 km Using Microwave QPSK Modulation , 1989 .

[2]  Douglas D. Tang.  Design and Performance of a Fiber-Optic Video Distribution System Using BPSK Microwave Subcarries , 1990, IEEE J. Sel. Areas Commun..

[3]  R. W. Tkach,et al.  8 Gbit/s FSK modulation of DFB lasers with optical demodulation , 1989 .

[4]  J. L. Gimlett,et al.  Ten-to-twenty gigabit-per-second modulation performance of 1.5- mu m distributed feedback lasers for frequency-shift-keying systems , 1989 .

[5]  S. L. Woodward.  Lightwave CATV systems using frequency-modulated laser and interferometer , 1989 .

[6]  K. Petermann,et al.  Semiconductor laser noise in an interferometer system , 1981 .

[7]  L. Stulz,et al.  FDMA-FSK star network with a tunable optical filter demultiplexer , 1988 .

[8]  Chinlon Lin,et al.  160-channel FM-video transmission using optical FM/FDM and subcarrier multiplexing and an erbium doped optical fibre amplifier , 1990 .

[9]  Robert Olshansky,et al.  Twenty channel FSK subcarrier multiplexed optical communication system for video distribution , 1988 .

[10]  A.E. Willner,et al.  1.2 Gb/s closely-spaced FDMA-FSK direct-detection star network , 1990, IEEE Photonics Technology Letters.

[11]  A. Ebberg,et al.  Pattern-independent FSK heterodyne transmission with endless polarization control and a 119 photoelectrons/bit receiver sensitivity , 1989 .

[12]  J. L. Gimlett,et al.  A 2-Gbit/s optical FSK heterodyne transmission experiment using a 1520-nm DFB laser transmitter , 1987 .

[13]  R. Olshansky,et al.  Bandwidth efficient transmission of 4 Gb/s on two microwave QPSK subcarriers over a 48 km optical link , 1990, IEEE Photonics Technology Letters.

[14]  B. Strebel,et al.  Digital transmission of TV signals with a fiber-optic heterodyne transmission system , 1984, Journal of Lightwave Technology.

[15]  John G. Proakis,et al.  Digital Communications , 1983 .